1. Field of the Invention
The present invention relates to protection of glass panes during storm conditions and, more particularly, to structures positioned over glass panes to absorb forces from high winds and wind-borne debris to protect the glass panes from shattering and damage.
2. Discussion of the Prior Art
Protection of glass panes in buildings during storms has been a great problem in the past, and many efforts have been made to prevent the glass panes from shattering and falling into the building due to high winds, projectiles and debris thereby damaging the interior of the building due to the glass and due to wind and rain damage through the breached glass pane. Prior art attempts to protect glass panes in buildings from storm damage have included prefabricated storm shutters, plywood sheets, lamination systems and taping. Storm shutters are normally made of aluminum or other lightweight metal alloys, fiberglass, polyvinyl acrylate or other plastic. Storm shutters are fabricated to fit the exact measurements of window structures, including glass panes, to be protected and have the disadvantages of being expensive and requiring substantial time for fabrication such that storm shutters are not available unless ordered well in advance of a storm. Plywood sheets are generally sold in four-foot by eight-foot sheets with a thickness of ⅝ inch such that the plywood sheets weigh approximately 50 pounds each. The plywood sheets must be cut to fit the size of the window structures and are normally drilled and screwed into the building or window frame requiring craftsmanship, labor and hardware and, thus, having the disadvantages of being expensive and requiring substantial time to cover windows when a storm is approaching as well as being extremely heavy. Lamination systems, such as those supplied by 3M Corporation (e.g. Scotchshield) have the disadvantages of being films applied to the interior of the glass panes since they are designed to prevent shattered glass from collapsing to thereby prevent rain damage and glass fragments from becoming projectiles. The film is not particularly effective in preventing the glass from shattering and does not make the glass more shatter resistant. Since the film is usually on the interior of the glass, it cannot absorb enough energy from the glass fast enough to prevent a failure or fracture of the glass if the glass pane is struck by debris or projectiles. Accordingly, the primary use of lamination systems is to prevent shattered glass from falling apart. Taping of windows results, at best, in the holding of most of a fractured glass pane in place to reduce rain damage and the risk of individuals being cut.
U.S. Pat. No. 3,830,760 to Benngston and U.S. Pat. No. 4,596,725 to Kluth et al are exemplary of polyurethane foams and discuss one-component and two-component polyurethanes. U.S. Pat. No. 3,455,865 to Bolt et al, U.S. Pat. No. 3,486,918 to Motter, U.S. Pat. No. 4,636,543 to Helton, U.S. Pat. No. 5,020,288 to Swenson, U.S. Pat. No. 5,107,643 to Swenson, U.S. Pat. No. 5,143,949 to Grogan et al, U.S. Pat. No. 5,186,978 to Woodhall et al, U.S. Pat. No. 5,281,436 to Swidler, U.S. Pat. No. 5,302,413 to Woodhall et al, U.S. Pat. No. 5,362,786 to Woodhall et al, U.S. Pat. No. 5,411,760 to Woodhall et al and U.S. Pat. No. 5,523,117 to Woodhall et al, are representative of polymeric films or layers for glass and/or polymeric films or layers removable by peeling.
From the above, it will be appreciated that there is a great need for protection of glass panes in window structures installed in buildings due to storms where the protection can be quickly applied and is inexpensive while also being easily removed.